Clark



J. G CLARK.

Burglar Alarm.

Patented May 24, 1859.

ITED STATES PATENT QFFICE.

JOHN G. CLARK, OF AUGUSTA, GEORGIA, ASSIGNOR TO HIMSELF AND SAML. W. HATCH, OF SAME PLACE.

BURGLARS ALARM.

Specification of Letters Patent No. 24,177, dated May 24, 1859'.

T 0 all whom it may concern:

Be it known that I, JOHN G. CLARK, of Augusta, in the county of Richmond and State of Georgia, have invented a new and useful Improvement in Burglar Alarms, which I denominate the Mechanical Watchman; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, in which 4 Figure l, is a front inside view of a door with my improvement applied to it. Flg. 2, is a vertical section of the same.

Similar letters of reference, in each of the several figures indicate corresponding parts.

My invention relates to a burglar alarm which is applied to a door or window in such a manner as to be capable, by its gravity, of detaching itself and dropping onto the floor or other resisting object simultaneously with the opening of the door or window by burglars, and thus produce an alarm which will arouse the sleeper and warn him of approaching danger.

The nature of my invention consists first in the employment of one or more cap nipples on a suspended gravitating breech piece or plate to receive a percussion cap or caps, when said breech piece forms part of a portable burglar alarm.

It consists second in providing said suspended breech piece or plate with a vertical stem and arranging, to slide over said stem, a tubular weight so that when the alarm detaches from the door and strikes the floor, the percussive force of the breech piece and weight will explode the cap or caps and produce the desired alarm.

It consists third in arranging a spring on the stem of the breech piece between the breech piece and weight so that the weight and breech piece shall be held far enough apart to allow the necessary movement of the same toward each other, to explode the cap or caps, when the alarm strikes the floor.

It consists fourth in providing serrations on the underside'of the suspending bracket, so that said bracket shall move with the door until it clears the framing.

To enable others, skilled in the art, to make and use my invention I will proceed to describe its construction and operation.

A, represents a portable bracket, with serunder the bracket free of the same and thus v render uncertain the operation of the alarm.

B, is a blank breech piece and C, cap nipple or nipples made solid or otherwise so as to answer the purpose intended, formed on the upper surface of the same. This breech piece may be convex on its under surface so as to insure the rebound of the breech piece no matter how it strikes the floor, in such a manner as will cause it to strike the weight squarely or nearly so. From the upper surface of the breech piece a vertical stem D, projects and said stem attaches to a chain or cord E, which hangs down from the outer end of the bracket A.

F, is a tubular weight arranged loosely on the stem so as to move up and down over the same. Above the weight, a shoulder a,

is formed' on the stem so as to prevent the weight getting detached from the stem and between the bottom of the weight and the top of the breech piece a spiral spring I), is placed, said spring being arranged over the stem D, and serving to hold the breech piece and weight far enough apart to allow the necessary movement of the same toward each other when the former strikes the floor, to effect the explosion of the cap.

From the above description it will be evident that if the parts are adjusted, caps placed on the nipples and the alarm applied to the door as shown, when the door is opened so that the inner end of the bracket clears the framing, the alarm will, by its gravity, detach from the door and fall to the floor and in falling the breech piece will strike the floor, rebound and thus overcome the spring and meet the descending weight with sufficient force to explode the caps and thus produce an alarm sufficient to wake up the sleeper in the room.

What I claim as my invention and desire to secure by LettersPatent, is

1. The employment of one or more cap nipples C, on a suspended gravitating breech piece or plate to receive a percussion cap or caps, when said breech piece forms part of a burglar alarm, substantially as and for the purpose set forth.

2. Providing said suspended breech piece or plate witha vertical stem and arranging to slide over said stem, a tubular weight so that when the alarm detaches from the door and strikes the floor, the percussive force of the breech piece and Weight will explode the cap or caps and produce the desired alarm substantially as set forth.

3. Arranging a spring on the stem of the breech piece, between the breech piece and Weight so that the same shall be held far enough apart to allow the necessary movement of the same toward each other to ex- I plode the cap or caps when the alarm strikes the floor, substantially as set forth.

4:. Providing serrations on the underside 15 of the suspending bracket, so that said bracket shall move with the door until it clears the framing, substantially as and for the purposes set forth.

JOHN G. CLARK.

Witnesses:

G. YORKE ATLEE, H. H. YOUNG, 

